Traping Error user input

2012 4 13
2 个回答
回答已采纳
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0 个投票

n=inputdlg('Please input a number more than or equal one:')
I would like to trap the user if they input anything other than numbers more than 1. I have tried loop,isnumeric but they all don't work overally.
Any ideas?
Thank you

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 采纳的回答

Honglei Chen
Honglei Chen 2012-4-13

0 个投票

Is this what you want?
n=inputdlg('Please input a number more than or equal one:')
while isempty(str2num(n{1})) || str2num(n{1})<1
n=inputdlg('Please input a number more than or equal one:')
end

5 个评论
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Rooy
Rooy 2012-4-13
This way doesn't really work
n =
'b'
Undefined function 'isnumeic' for input arguments of type 'cell'.
Error in Untitled23 (line 2)
while ~isnumeic(n) || n < 1
If I extract from the cell array it would still not work
Honglei Chen
Honglei Chen 2012-4-13
I didn't realize you are using inputdlg and I had a typo. I updated the answer
Rooy
Rooy 2012-4-13
Thank you it works.
Rooy
Rooy 2012-4-14
What if I have more than one input
for instance
n=inputdlg({'Please input a number more than or equal one:';'P'})
while isempty(str2num(n{1})) || str2num(n{1})<1 || isempty(str2num(n{2})) || str2num(n{2})<1
h = errordlg;
waitfor(h)
n=inputdlg({'Please input a number more than or equal one:';'P'})
end
I can't just keep hard coding the loops based on the the amount of inputs. Is there another way
Honglei Chen
Honglei Chen 2012-4-15
n=inputdlg({'Please input a number more than or equal one:';'P'})
while any(cellfun(@isempty,cellfun(@str2num,n,'UniformOutput',false))) || ...
any(cellfun(@lt,cellfun(@str2num,n,'UniformOutput',false),...
num2cell(ones(numel(n),1))))
h = errordlg;
waitfor(h)
n=inputdlg({'Please input a number more than or equal one:';'P'})
end

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更多回答（1 个）

Image Analyst
Image Analyst 2012-4-13

0 个投票

Try this:
clc; % Clear the command window.
workspace; % Make sure the workspace panel is showing.
fontSize = 20;
format compact;
% Initialize flag to keep going or not.
keepGoing = true;
userPrompt = 'Enter a number greater than 1';
defaultValue = 42;
while keepGoing
% Ask user for a number.
caUserInput = inputdlg(userPrompt, 'Enter the number',1,{num2str(defaultValue)});
usersValue = round(str2double(cell2mat(caUserInput)));
% Check for a valid integer.
if isnan(usersValue)
% They didn't enter a number.
% They clicked Cancel, or entered a character, symbols, or something else not allowed.
break;
end
% See if it's > 1
if usersValue > 1
message = sprintf('Success!\n you entered %f.\n', usersValue);
keepGoing = false; % Bail out
else
message = sprintf('Try again. You entered %f.\n%s', ...
usersValue, userPrompt);
% Keep going.
end
uiwait(msgbox(message));
end

4 个评论
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Rooy
Rooy 2012-4-13
It stalls when I enter the right input after entering a few bad ones.
Thank you
Rooy
Rooy 2012-4-13
Where could I get to reprompt the user to enter again?
Thank you
Image Analyst
Image Analyst 2012-4-14
It does not stall. It works fine. I just copied it and ran it again. I was able to enter lots of numbers less than 1 and it kept reprompting the user to enter a number >1. When I finally did enter a number > 1, it exited the while loop. It does exactly what you asked for. If it doesn't, then you must have altered it and broken it.
Rooy
Rooy 2012-4-17
Thank you for all the help

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